This invention relates to waterbed mattresses.
Waterbed mattresses are conventionally made of plasticized polyvinylchloride. Polyvinylchloride is an advantageous material to use in that it is durable, flexible, and can easily be bonded to itself by adhesives and heat for forming sheets of polyvinylchloride into the configuration of a waterbed.
However, polyvinylchloride suffers from a disadvantage. A polyvinylchloride mattress can be punctured or torn by misuse from the owner of a waterbed mattress. It is common for an owner of a waterbed mattress, forgetting that he does not have a conventional mattress, to stick a pin into the mattress, thereby causing a leak. Also, cats and other domestic animals are known to rip waterbed mattresses.
There has been no solution to the problem, although attempts have been made to cure its symptoms. These attempts involve the use of exterior waterproof covers around the mattress so as to prevent leaking water from spilling onto surrounding floor surfaces. Such exterior liners are described in U.S. Pat. Nos. 3,761,974; 3,736,604; 3,742,531; 4,149,286; and 4,145,780. However, although these liners can contain leaks, they do nothing to solve the problem of a punctured waterbed mattress.